Camera device

Abstract

According to the present disclosure, there is provided an imaging device, comprising: a first semiconductor layer (180) formed on a semiconductor substrate; a second semiconductor layer (170) formed on the first semiconductor layer (180) and having a conductivity type opposite to that of the first semiconductor layer (180); a pixel separation portion (150) dividing a pixel region including the first semiconductor layer (180) and the second semiconductor layer (170); a first electrode (130) connected to the first semiconductor layer (180) from one surface side of the semiconductor substrate; and a metal layer (152) connected to the second semiconductor layer (170) from a light irradiation surface side of the other surface of the semiconductor substrate, wherein the metal layer (152) is buried in the pixel separation portion (150) at least partially in the thickness direction of the semiconductor substrate.

Description

Technical Field

[0001] The present disclosure relates to an imaging device. Background Art

[0002] For example, in the prior art, the following patent document 1 discloses a single photon avalanche diode (SPAD) structure, in which a first semiconductor layer as a first buried layer of a first conductivity type and a second semiconductor layer of a second conductivity type opposite to the first conductivity type located below the first semiconductor layer are provided. The second semiconductor layer is buried in an epitaxial layer, and the second semiconductor layer is completely formed into a depletion layer by applying a bias voltage.

[0003] [Citation List]

[0004] [Patent Document]

[0005] [Patent Document 1]

[0006] JP 2015-41746A Summary of the invention

[0007] [Technical issues]

[0008] In SPAD technology, incident light can be extracted as a large signal by applying a large bias voltage and multiplying electrons. In the structure disclosed in Patent Document 1, a pair of electrodes for applying a high voltage is arranged on the front surface of the substrate. Therefore, in order to reduce noise or improve the photoelectric conversion efficiency, it is necessary to reliably insulate the pair of electrodes from each other. In particular, as miniaturization proceeds, it becomes more difficult to insulate a pair of electrodes, so it is difficult to achieve miniaturization while reducing noise, improving photoelectric conversion efficiency, etc.

[0009] When a pair of electrodes are provided on the front and rear surfaces of a substrate, an electrode provided using a transparent electrode or an impurity layer is provided on the light irradiation surface. However, in the case of providing a transparent electrode, noise is sometimes generated at the contact portion with the substrate. When an electrode is formed using an impurity layer, it is necessary to inject high-concentration impurities. Although a depletion layer cannot be formed in the region of the impurity layer, it is necessary to ensure the thickness of the impurity layer to achieve low resistance of the electrode. In this case, in particular, there is a problem of reduced sensitivity to light with a short wavelength.

[0010] Therefore, it is necessary to achieve pixel miniaturization, noise reduction, and high quantum efficiency, and to improve short-wavelength sensitivity while suppressing interference between pixels and differences in each pixel.

[0011] [Technical solutions to technical problems]

[0012] According to the present disclosure, there is provided an imaging device, which includes: a first semiconductor layer formed on a semiconductor substrate; a second semiconductor layer formed on the first semiconductor layer and having a conductivity type opposite to that of the first semiconductor layer; a pixel separation portion configured to divide a pixel area including the first semiconductor layer and the second semiconductor layer; a first electrode connected to the first semiconductor layer from one surface side of the semiconductor substrate; and a metal layer connected to the second semiconductor layer from a light irradiation surface side which is the other side of the semiconductor substrate, and the metal layer is buried in the pixel separation portion in at least a portion of the semiconductor substrate in a thickness direction.

[0013] [Beneficial effects of the present invention]

[0014] According to the present disclosure, as described above, pixel miniaturization, noise reduction, and high quantum efficiency can be achieved, and short-wavelength sensitivity can be improved while suppressing interference between pixels and variation per pixel.

[0015] The aforementioned beneficial effects are not necessarily limitative, and any beneficial effects described in this specification or other beneficial effects that can be determined from this specification can be obtained in addition to or instead of the aforementioned beneficial effects. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 is a schematic diagram showing a configuration example in which a SPAD photodiode is set to a back-illuminated type, one anode electrode is provided on the back side, and a high voltage is applied.

[0017] Figure 2 is a schematic diagram showing a semiconductor device (SPAD photodiode) according to an embodiment of the present disclosure.

[0018] Figure 3 is a schematic diagram showing another configuration example according to the embodiment.

[0019] Figure 4 The back side is shown as Figure 3 Schematic diagram of the structure of the buried metal layer in the structure shown.

[0020] Figure 5 It shows that Figure 2 A schematic diagram of an example in which an auxiliary electrode with an anode electrode is provided on the outermost surface of a pixel region in a configuration example shown.

[0021] Figure 6 It shows that Figure 2 A schematic diagram of an example in which an insulating layer is provided on the outermost surface of a photoelectric conversion portion within the range of a pixel separation portion and a metal layer having a light-shielding property is provided on the insulating layer in the illustrated configuration example.

[0022] Figure 7 is a schematic diagram showing an example in which a metal layer having a light-shielding property is provided on an anode electrode and no insulating layer is provided on a pixel separation portion.

[0023] Figure 8 It shows that Figure 3 A schematic diagram of an example in which an insulating layer is provided on a light irradiation surface without providing a metal layer having a light shielding property in the illustrated configuration example.

[0024] Fig. 9 It shows that Figure 3 In the construction example shown Figure 6 This is a schematic diagram of an example in which an insulating layer and a metal layer having a light-shielding property are provided identically in the illustrated configuration example.

[0025] Fig.10 It shows that Figure 3 In the construction example shown Figure 7 This is a schematic diagram of an example in which an insulating layer and a metal layer having a light-shielding property are provided identically in the illustrated configuration example.

[0026] Fig.11 It shows that Figure 4 A schematic diagram of an example in which the configuration example shown is provided with an anode electrode at a position closer to the pixel region side than the pixel separating portion and the anode electrode is connected to a surface metal layer provided on the pixel separating portion.

[0027] Fig.12 It shows that Figure 1 The schematic diagram of the example in which the length of the buried metal layer in the depth direction of the pixel region is short among the structural examples shown.

[0028] Fig.13 is a schematic diagram showing the positional relationship between an anode electrode and an electrode connected to the anode electrode.

[0029] Fig.14 is a schematic diagram showing the positional relationship between an anode electrode and an electrode connected to the anode electrode.

[0030] Fig.15 is a schematic diagram showing the positional relationship between an anode electrode and an electrode connected to the anode electrode.

[0031] Fig.16 is a plan view showing the positional relationship between the anode electrode and the contact layer.

[0032] Fig.17 is a plan view showing the positional relationship between the anode electrode and the contact layer.

[0033] Fig.18It shows that Fig.12 This is a schematic cross-sectional view of a configuration in which a color filter is provided on an insulating layer on a light irradiation surface, and an on-chip lens is further provided on the color filter.

[0034] Fig.19 It shows that from Fig.18 FIG. 1 is a schematic diagram showing a state in which the region of the photoelectric conversion region is viewed from the boundary surface between the insulating layer and the photoelectric conversion region.

[0035] Fig. 20 : is a block diagram showing a configuration example of a camera device as an electronic device to which the present technology is applied.

[0036] Fig.21A It is a schematic cross-sectional view showing a basic structure common to each modification example.

[0037] Fig. 21B is shown where the metal layer is connected with Fig.18 The insulating film is covered with the same insulating film and Fig.21A Schematic cross-sectional view of an example in which a color filter is provided.

[0038] Fig.22A 1 is a schematic cross-sectional view showing in detail the vicinity of a pixel separation unit of the image pickup device according to the first modification.

[0039] Fig. 22B is a schematic cross-sectional view showing another aspect of the image pickup device according to the first modification.

[0040] Fig. 22C is a schematic cross-sectional view showing still another aspect of the image pickup device according to the first modification.

[0041] Fig.22D is a schematic cross-sectional view showing still another aspect of the image pickup device according to the first modification.

[0042] Fig.22E is a schematic cross-sectional view showing still another aspect of the image pickup device according to the first modification.

[0043] Fig.22F is a schematic cross-sectional view showing still another aspect of the image pickup device according to the first modification.

[0044] Figure 22G is a schematic cross-sectional view showing still another aspect of the image pickup device according to the first modification.

[0045] Fig.22H is a schematic cross-sectional view showing still another aspect of the image pickup device according to the first modification.

[0046] Fig.23Ais a plan view showing an image pickup device according to a first modification.

[0047] Fig. 23B is a plan view showing an image pickup device according to a first modification.

[0048] Fig.23C is a plan view showing an image pickup device according to a first modification.

[0049] Fig.23D is a plan view showing an image pickup device according to a first modification.

[0050] Fig.23E is a plan view showing an image pickup device according to a first modification.

[0051] Fig.23F is a plan view showing an image pickup device according to a first modification.

[0052] Figure 23G is a plan view showing an image pickup device according to a first modification.

[0053] Fig.24 Schematic cross-sectional views showing a method for manufacturing a semiconductor device according to a first modification example in order of steps.

[0054] Fig.25 It is shown in Fig.24 This is a schematic diagram of a manufacturing process in which a second buried layer formed from the front surface side to the back surface side is surrounded by a high-concentration P layer using solid diffusion or the like in the manufacturing method shown.

[0055] Fig.26 is a schematic cross-sectional view showing an image pickup device according to a second modification.

[0056] Fig. 27 is a schematic cross-sectional view showing an image pickup device according to a third modification example.

[0057] Fig.28 It is shown Fig. 27 A schematic diagram of an enlarged range of area A1 is shown.

[0058] Fig.29 is a schematic cross-sectional view showing another example of the third modification.

[0059] Fig.30 It is shown Fig.29 A schematic diagram of an enlarged range of area A2 is shown.

[0060] Fig.31 Schematic cross-sectional views showing a method for manufacturing a semiconductor device according to a third modification example in order of steps.

[0061] Fig.32 It is shown in Fig.31 A schematic cross-sectional view of an example of further forming an insulating film in a groove when the insulating film formed in the first buried layer in the groove retreats in step (5) of .

[0062] Fig.33 It is shown in Fig.32 The cross-sectional view of the enlarged area A3 in the step (5-1) and the step (5-2) shown.

[0063] Fig.34 is a schematic diagram showing the configuration of an electronic device including an imaging device.

[0064] Fig.35 is a block diagram showing an example of a schematic configuration of a vehicle control system.

[0065] Fig.36 It is an explanatory diagram showing an example of the installation positions of the vehicle exterior information detection unit and the imaging unit.

[0066] Fig.37 is a diagram showing an example of a schematic configuration of an endoscopic surgery system.

[0067] Fig.38 is a block diagram showing an example of the functional configuration of a camera and a CCU. DETAILED DESCRIPTION

[0068] Hereinafter, preferred embodiments of the present disclosure will be described with reference to the accompanying drawings. In this specification and the accompanying drawings, the same reference numerals are given to constituent elements having substantially the same functional configuration, and description thereof will be omitted.

[0069] The description will be given in the following order. 1. Background Technology

[0071] 2. Configuration Example of Image Capture Device According to Embodiment

[0072] 3. Other Configuration Examples of the Image Capture Device According to the Embodiment

[0073] 4. Lead the anode electrode to the outside

[0074] 5. Positional relationship between anode electrode and contact layer

[0075] 6. Example of a construction including a color filter and a lens

[0076] 7. Application Examples of the Image Capture Device According to the Embodiment

[0077] 8. Modifications of the present disclosure

[0078] 8.1. General structure

[0079] 8.2. First Modification

[0080] 8.3. Second Modification

[0081] 8.4. Third Modification

[0082] 9. Application examples other than imaging devices

[0083] 10. Example of electronic device construction

[0084] 11. Application examples for mobile objects

[0085] 12. Application examples of endoscopic surgery systems 1. Background Technology

[0087] There is a single photon avalanche diode (SPAD) technology that can realize a photodiode with a read sensitivity of 1 photon level by multiplying electrons. In order to realize multiplication in SPAD, a high voltage of about ± tens of volts is required. Therefore, it is difficult to design the injection of impurities and to achieve miniaturization while reducing noise and improving photoelectric conversion efficiency. Therefore, as Figure 1 As shown, there is a technique in which a SPAD photodiode is formed as a back-illuminated type, an anode electrode 1130 is provided on the back side, and a high voltage is applied, thereby solving the problem of relaxation of the lateral electric field and generating a deep depletion layer. Figure 1 In the structure shown, a high electric field multiplication region is formed between a high concentration P-type layer (second semiconductor layer) 1170 in contact with a P-type photoelectric conversion unit 1160 and an N-type layer (first semiconductor layer) 1180 of a cathode. The N-type layer 1180 is connected to a cathode electrode 1100. An electrode 1102 is connected to the front surface side of the cathode electrode 1100.

[0088] The anode electrode 1130 is led out on the front surface side. However, in order to relax the electric field between the cathode electrode 1100 and the contact portion on the front surface side, it is necessary to separate the contact portion from the cathode electrode 1100 sufficiently. Figure 1 In the illustrated configuration, a contact layer 1140 is provided outside the pixel array, the contact layer 1140 being connected to the anode electrode 1130 and leading the anode electrode 1130 to the front surface side.

[0089] On the other hand, in order to Figure 1In order to form the anode electrode 1130 on the irradiated surface of the back side in the back structure as in the embodiment, it is necessary to use a transparent electrode as the anode electrode 1130. In the method of forming the anode electrode 1130 using a transparent electrode (for example, ITO) and contacting the anode electrode 1130 with the photoelectric conversion unit 1160, noise is generated in the contact portion between the anode electrode 1130 and the photoelectric conversion unit 1160. Therefore, in some cases, an electrode is formed on the outermost surface of the photodiode, that is, on the outermost surface of the photoelectric conversion unit 1160, and a high-concentration impurity is injected into the electrode. However, when the high-concentration impurity is injected into the photoelectric conversion unit 1160, a depletion layer cannot be formed in this portion, and photoelectric conversion cannot be performed on the outermost surface of the photodiode. Therefore, the quantum efficiency of light with a short wavelength may be reduced. Therefore, it is necessary to thin the high-concentration impurity portion formed on the outermost surface of the photoelectric conversion unit 1160. However, when the high-concentration impurity portion is thinned, the resistance may increase. In particular, when the contact layer 1140 is provided outside the pixel array and the contact layer 1140 contacts the anode electrode 1130 on the back side, the advantage of miniaturization is obtained. However, the resistance from the contact layer 1140 to the pixel increases, and the voltage may change when the large multiplication current unique to the SPAD flows. This change also affects other pixels, and inter-pixel interference indicating a change in the characteristics of other pixels may occur.

[0090] In view of the above, according to the embodiment, while providing a back electrode structure capable of realizing miniaturized pixels, interference between pixels caused by voltage changes in the electrodes is suppressed, and quantum efficiency is particularly improved on the short wavelength side.

[0091] 2. Configuration Example of Image Capture Device According to Embodiment

[0092] Figure 2 1 is a schematic diagram showing an imaging device (SPAD photodiode) 1000 according to an embodiment of the present disclosure. Figure 2 The structure shown includes a multiplication region used as a SPAD pixel and a photoelectric conversion unit 160 for performing photoelectric conversion. The structure includes a cathode electrode 100 and an anode electrode 130 . Figure 2The configuration shown is a back-illuminated pixel, the substrate of the photodiode is thinned to less than or equal to 10 μm, and an anode electrode 130 is provided on the back side, one of a pair of electrodes to which a high voltage is applied. The front surface side of the semiconductor substrate 50 is the side on which the wiring layer is formed on the semiconductor substrate 50. In the image pickup device 1000 according to the embodiment, the back side of the semiconductor substrate 50 is set as a light irradiation surface. The anode electrode 130 on the back side is set to correspond to the pixel separation section 150. The thickness of the anode electrode 130 is equal to or greater than, for example, 500 nm, and the anode electrode 130 serves as a low resistance electrode. A photoelectric conversion section 160 is provided in the pixel region between the pixel separation sections 150, and the outermost surface on the back side of the photoelectric conversion section 160 serves as a light irradiation portion irradiated with light. The pixel region is defined by the distance of the pixel separation section 150, and the pixel region has a rectangular planar shape, the length and width of which are equal to or less than 5 μm. The anode electrode 130 is connected to a contact layer 140 formed by deep implantation of impurities, buried metal, etc. outside the pixel array, and the potential is extracted to the front surface side. By applying a predetermined voltage to the electrode 142 connected to the contact layer 140 on the front surface side, the predetermined voltage is applied to the anode electrode 130 via the contact layer 140. The contact layer 140 preferably surrounds the pixel array. The contact layer 140 may be located at one location, or may be divided into a plurality of pieces. For the anode electrode 130, a plurality of contact layers 140 may be formed inside the pixel array. As the number of contact layers 140 for obtaining electrodes increases, voltage changes in the anode electrode 130 on the back side can be suppressed.

[0093] like Figure 2 As shown, in the pixel array, pixels are separated by a pixel separation unit 150. Figure 2 , one pixel in the pixel array is shown. The pixel separation unit 150 is formed by changing the polarity of impurities using the photoelectric conversion unit 160. Figure 2 In the embodiment, the anode electrode 130 on the back side is set to a position corresponding to the pixel separation unit 150 and is set just above the pixel separation unit 150. The pixel separation unit 150 is formed by high-concentration impurity injection, and the anode electrode 130 is formed to have a sufficient thickness equal to or greater than, for example, 500 nm so as to sufficiently reduce the resistance. With this structure, the depletion layer of the photoelectric conversion unit 160 can be formed to the outermost surface on the back side of the pixel, and the sensitivity of the short wavelength can be sufficiently maintained.

[0094] exist Figure 2In the embodiment, an N-type impurity layer is formed on the front surface side and used as a cathode electrode 100, and a P-type impurity layer is formed on the back side and used as an anode electrode 130. An N-type layer (first semiconductor layer) 180 is connected to the cathode electrode 100. An electrode 102 is connected to the surface side of the cathode electrode 100. The photoelectric conversion unit 160 connected to the anode electrode 130 is a low-concentration P-type, and a high-electric-field multiplication region is formed between the N-type layer 180 of the cathode and the high-concentration P-type layer (second semiconductor layer) 170 connected to the photoelectric conversion unit (third semiconductor layer) 160. The low-concentration N-type layer is used as a pixel separation unit 150. The photoelectric conversion unit 160 may not be provided, and the P-type layer 170 may extend to the region of the photoelectric conversion unit 160.

[0095] The conductivity type and concentration of the impurity layer are exemplary, and P and N can be interchanged with each other, and the anode and cathode can be set to opposite conductivity types. Various other methods can be considered as a method of generating a multiplication region as a high electric field. In addition, an impurity injection region for separating the multiplication region can be provided, or a buried insulating film or the like can be provided as the pixel separation portion 150.

[0096] As described above, in the embodiment, in the back-illuminated SPAD, the front and rear surfaces of the substrate have the anode electrode 130 and the cathode electrode 100. The anode electrode 130 on the back side is provided in the pixel separation unit 150. Therefore, since the photoelectric conversion unit 160 formed by the depletion layer can extend to the outermost surface of the light irradiation surface, the short wavelength sensitivity can be greatly improved. When the pixel is relatively large, since the anode electrode 130 is located at the pixel end, the electric field in the pixel is not constant, and the depletion layer is difficult to extend to the front surface of the photoelectric conversion unit 160 in the middle of the pixel. However, since the potential from the pixel end also reaches the center of the pixel in the tiny pixel, it is possible to adopt a structure in which the anode electrode 130 on the back side is provided in the pixel separation unit 150.

[0097] Figure 3 1 is a schematic diagram showing another configuration example according to the embodiment, and shows an example in which a metal layer 152 having a light shielding property is used as a pixel separation unit 150 on the pixel surface on the back side. Therefore, it is also possible to reduce the resistance of the anode electrode 130 on the back surface while reducing the interference between pixels due to light, and further suppress the pixel interference due to voltage changes. The metal layer 152 can be formed of a metal such as tungsten (W). Figure 2 As in the embodiment, a high concentration impurity implantation region is provided directly below the metal layer 152 and serves as the anode electrode 130. The metal layer 152 and the anode electrode 130 formed by the high concentration impurity region may be in contact with each other. Figure 3 In the case of the structural example shown in FIG. Figure 2The lead-out may be made on the front surface side as in the example, or the lead-out may be made on the back surface side directly connected to the bonding pad.

[0098] The pixel separation part 150 has a grid-shaped planar shape and surrounds a rectangular pixel region. Therefore, the anode electrode 130 formed on the pixel separation part 150 and the metal layer 152 formed on the anode electrode 130 can have a planar shape similar to the grid shape of the pixel separation part 150.

[0099] exist Figure 3 In the example shown, a buried metal layer 190 having a light-shielding property is buried in the pixel separation unit 150 on the front surface side. Like the metal layer 152, the buried metal layer 190 can be formed of a metal such as tungsten (W). In this case, the buried metal layer 190 and the photoelectric conversion unit 160 are separated by an insulating film 194, and the buried metal layer 190 is surrounded by the insulating film 194 between adjacent pixels in the pixel area. In this structure, inter-pixel interference occurring in a deeper area of ​​the pixel area can be suppressed, and a structure that is advantageous in terms of miniaturization and in which the anode electrode 130 is provided on the back side can be combined. The buried metal layer 190 is buried from the front surface side to the middle part of the photoelectric conversion unit 160, and a high-concentration impurity region is generated directly above the buried metal layer 190 to serve as the anode electrode 130 on the back side.

[0100] exist Figure 4 In the example shown, a Figure 3 The buried metal layer 190 of the structure shown. In this case, the anode electrode 130 formed by the high-concentration impurity region is formed in the pixel region and surrounds the buried metal layer 190. However, since the buried metal layer 190 is provided and the connection between the pixels of the anode electrode 130 is cut off, a metal layer 152 is provided on the pixel separation unit 150, and the metal layer 152 and the anode electrode 130 are in contact to connect the anode electrode 130 between pixels. The metal layer 152 is insulated from the buried metal layer 190. The buried metal layer 190 can be buried in only a part of the photoelectric conversion unit 160, and more preferably buried in the entire pixel region. With this structure, miniaturization and high quantum efficiency can be achieved by completely blocking the inter-pixel interference caused by light while also suppressing the inter-pixel interference caused by voltage changes, so that low-noise pixels can be achieved.

[0101] As described above, in the embodiment, the anode electrode 130 is formed to correspond to the position of the pixel separation portion 150. Assume that the anode electrode 130 is formed corresponding to the position of the pixel separation portion 150 includes the following cases: Figure 2 When the anode electrode 130 is formed directly above the pixel separation unit 150 as in Figure 4Although the anode electrode 130 is formed to correspond to the position of the pixel separation portion 150, it may not be provided to correspond to all the pixel separation portions 150, or may be provided to correspond to only a part of the pixel separation portion 150.

[0102] 3. Other Configuration Examples of the Image Capture Device According to the Embodiment

[0103] In the following, we will base on Figures 2 to 4 The configuration examples shown are provided to explain several modifications of the embodiment. Figure 5 The configuration example shown is an example in which, relative to Figure 2 The illustrated construction example provides an auxiliary electrode 132 with an anode electrode 130 on the outermost surface of the pixel region. The auxiliary electrode 132 is formed to have the same conductivity type as the anode electrode 130. The thickness of the auxiliary electrode 132 is, for example, 50 nm or less, so that the region of the photoelectric conversion unit 160 can be ensured as much as possible. In this way, the auxiliary electrode 132 can be provided on the outermost surface of the back side within the pixel by injecting high-concentration impurities. Here, the thickness of the auxiliary electrode 132 in the region where the impurities are injected within the pixel is made sufficiently thin, and an appropriate thickness is, for example, equal to or less than 50 nm. Figure 5 In the example shown, an insulating layer 200 is provided on the auxiliary electrode 132, and the photoelectric conversion unit 160 is irradiated with light through the insulating layer 200. By providing the auxiliary electrode 132, the potential of the outermost surface on the back side of the photoelectric conversion unit 160 can be made constant, so the depletion layer can be expanded and the electric field in the multiplication region can be made uniform in the pixel. Since the thickness of the auxiliary electrode 132 is thin, the resistance of the auxiliary electrode 132 is high, and there is no effect on the short wavelength sensitivity. However, since the resistance of the anode electrode 130 provided in the pixel separation unit 150 is low, the potential change of other pixels does not occur.

[0104] Figure 6 The configuration example shown is an example in which, relative to Figure 2 In the illustrated configuration example, the insulating layer 200 is provided on the outermost surface (light irradiation surface) of the photoelectric conversion portion 160 and the metal layer 152 having a light shielding property is provided on the insulating layer 200 within the range of the pixel separation portion 150 . Figure 7 The illustrated configuration example is an example in which a metal layer 152 having a light shielding property is provided on the anode electrode 130, and an insulating layer 200 is not provided on the pixel separation portion 150. By providing the metal layer 152 having a light shielding property, the light incident path can be divided for each pixel. Figure 7 In the illustrated configuration example, the anode electrode 130 and the metal layer 152 having a light shielding property can have the same potential.

[0105] Figure 8 The configuration example shown is an example in which Figure 3 The illustrated configuration example is one in which the insulating layer 200 is provided on the light irradiation surface without providing the metal layer 152 having a light shielding property. Fig. 9 The configuration example shown is an example in which, as Figure 6 The construction example shown in Figure 3 In the illustrated configuration example, an insulating layer 200 and a metal layer 152 having a light shielding property are provided. Fig.10 The configuration example shown is an example in which, as Figure 7 The construction example shown in Figure 3 In the illustrated configuration example, an insulating layer 200 and a metal layer 152 having a light shielding property are provided.

[0106] Fig.11 The configuration example shown is an example in which Figure 4 In the illustrated configuration example, the anode electrode 130 is disposed at a position closer to the pixel region side than the pixel separation portion 150 and the surface metal layer 220 disposed on the pixel separation portion 150 is connected to the anode electrode 130. The anode electrode 130 is connected to the anode electrode 130 of the adjacent pixel region through the surface metal layer 220. Therefore, the surface metal layer 220 is formed on the pixel separation portion 150. Fig.12 The configuration example shown is an example in which, relative to Figure 1 The illustrated configuration example shortens the length of the buried metal layer 190 in the depth direction of the pixel region (photoelectric conversion unit 160 ).

[0107] 4. Lead the anode electrode to the outside

[0108] Figures 13 to 15 1 is a schematic diagram showing a positional relationship between the anode electrode 130 and an electrode 142 connected to the anode electrode 130. Here, the electrode 142 is provided outside the pixel array, and functions as a bonding pad (extraction electrode). Fig.13 An example is shown in which, by Figure 2 The contact layer 140 is provided as in the embodiment of the present invention, and the anode electrode 130 is led out to the front surface side via the contact layer 140, and the contact layer 140 is connected to the electrode 142 on the front surface side. The contact layer 140 can be connected to the peripheral circuit of the pixel array.

[0109] Fig.14 The example shown is an example in which the electrode 142 is provided on the same back side as the anode electrode 130, and the anode electrode 130 and the electrode 142 are directly connected. Fig.14 In the example shown, an electrode 142 serving as a bonding pad is provided on the back side. Fig.14In the embodiment, a metal layer 152 having a light shielding property may be provided on the anode electrode 130, and the metal layer 152 may be connected to the electrode 142 serving as a bonding pad.

[0110] Fig.15 The example shown is an example where, for example Fig.13 In the example shown, an electrode 142 is provided on the front surface side, and Fig.15 1 is a schematic diagram showing an example in which a metal layer 152 connected to the anode electrode 130 is provided and the metal layer 152 is connected to the contact layer 140 via the anode electrode 130 .

[0111] 5. Positional relationship between anode electrode and contact layer

[0112] Fig.16 and Fig.17 1 is a plan view showing the positional relationship between the anode electrode 130 and the contact layer 140, and shows a state viewed from the light irradiation surface side (back side). Fig.16 and Fig.17 In FIG. 1 , the inner side of the single-point dash line R is the area within the pixel array, and the outer side of the single-point dash line R is the area outside the pixel array. Fig.16 As shown, since the anode electrode 130 is arranged along the pixel separation portion 150 in the pixel array, the anode electrode 130 is in a lattice shape. When the metal layer 152 having a light shielding property is formed, a lattice-shaped metal layer 152 having a light shielding property can be arranged on the anode electrode 130. Fig.16 The metal layer 152 of the anode electrode 130 is shown in a grid shape. The metal layer 152 having a light shielding property is closer to the periphery in the pixel array, so that its position is further away from the pixel separation unit 150, so that correction can be made according to the pupil position and the light shielding effect can be improved. In particular, when Figure 6 When the metal layer 152 having light shielding properties is formed on the anode electrode 130 via the insulating layer 200 as in the above, the metal layer 152 and the anode electrode 130 are not integrated. Therefore, the metal layer 152 can be positioned closer to the periphery in the pixel array, so that its position can be further away from the pixel separation unit 150 (anode electrode 130). Figure 2 As shown, the contact layer 140 is provided to surround the pixel array, and the anode electrode 130 is led out on the front surface side via the contact layer 140. By providing the contact layer 140 in the periphery outside the pixel array, voltage variation inside the anode electrode 130 can be reliably suppressed.

[0113] Fig.17 It shows that except Fig.16 In addition to the structure of FIG. 1 , a contact layer 140 is also provided in the pixel array. Fig.17As shown, by also providing a contact layer 140 in the pixel array, the potential of the anode electrode 130 can be further stabilized.

[0114] 6. Example of a construction including a color filter and a lens

[0115] Fig.18 is a schematic cross-sectional view showing the following configuration, wherein Fig.12 In the illustrated configuration, color filters 300a, 300b, and 300c are provided on the insulating layer 200 on the light irradiation surface, and an on-chip lens 400 is further provided on the color filters 300a, 300b, and 300c. The photoelectric conversion unit 160 is irradiated with light that passes through the on-chip lens 400 and the color filters 300a, 300b, and 300c. Fig.18 middle, Fig.12 The insulating film 194 of the pixel separation portion 150 shown is generally provided in the insulating layer 200 of the light irradiation surface.

[0116] Fig.19 It is shown from Fig.18 Schematic diagram showing the state of the photoelectric conversion unit 160 region observed from the boundary surface between the insulating layer 200 and the photoelectric conversion unit 160. Fig.19 As shown, the pixel separation section 150 is provided by the buried metal layer 190 and the insulating layer 200 (insulating film 194), and the pixel region formed by the photoelectric conversion section 160 is demarcated by the pixel separation section 150. Fig.19 In each of the photoelectric conversion portions 160 shown, the anode electrode 130 is provided so as to surround the pixel region along the pixel separation portion 150 .

[0117] 7. Application Examples of the Image Capture Device According to the Embodiment

[0118] Fig. 20 is a block diagram showing a configuration example of a camera device 2000 as an electronic device to which the present technology is applied. Fig. 20 The camera device 2000 shown includes an optical unit 2100 formed of a lens group and the like, the above-mentioned image pickup device 1000, and a DSP circuit 2200 as a camera signal processing device. The camera device 2000 also includes a frame memory 2300, a display unit (display device) 2400, a recording unit 2500, an operation unit 2600, and a power supply unit 2700. The DSP circuit 2200, the frame memory 2300, the display unit 2400, the recording unit 2500, the operation unit 2600, and the power supply unit 2700 are connected to each other via a bus 2800.

[0119] The optical unit 2100 acquires incident light (image light) from a subject and forms an image on an imaging surface of the imaging device 1000. The imaging device 1000 converts the light amount of the incident light formed as an image on the imaging surface by the optical unit 2100 into an electrical signal in units of pixels and outputs the electrical signal as a pixel signal.

[0120] The display unit 2400 is, for example, a panel type display device such as an organic electroluminescence (EL: electro-luminescence) panel or a liquid crystal panel, and the display unit 2400 displays a moving image or a still image captured by the camera device 1000. The DSP circuit 2200 receives a pixel signal output from the camera device 1000, and performs processing for displaying the pixel signal on the display unit 2400. The recording unit 2500 records the moving image or the still image captured by the camera device 1000 on a recording medium such as a video tape or a digital versatile disc (DVD).

[0121] The operation unit 2600 issues operation instructions for various functions of the imaging apparatus 1000 in response to user operations. The power supply unit 2700 appropriately supplies various power sources used as operation power sources for the DSP circuit 2200, frame memory 2300, display unit 2400, recording unit 2500, and operation unit 2600 to these power supply targets.

[0122] 8. Modifications of the present disclosure

[0123] Hereinafter, problems that arise when the present disclosure is specifically implemented and modifications of the embodiment for solving these problems will be described.

[0124] 8.1. General structure

[0125] First, a basic configuration common to each modification will be described. Fig.21A It is a schematic cross-sectional view showing a basic structure common to each modification example. Fig.21A The image pickup device 1000 shown includes a multiplication region serving as a SPAD pixel and a photoelectric conversion portion (N-region) 160 that performs photoelectric conversion. The outermost surface on the back side of the photoelectric conversion portion 160 serves as a light irradiation portion irradiated with light.

[0126] like Fig.21AAs shown, the metal layer 152 used as the anode electrode 130 is electrically connected to the P region 760. The P region 760 is constructed so that the impurity concentration in the lower layer is low. The P region 700 and the P- region 710 are formed along the pixel separation portion 150 from the P region 760, and the portion from the P region 760 to the avalanche portion 720 is electrically connected. The avalanche portion 720 is formed by joining the P+ region 730 and the N+ region 740. The P region 700 is formed by accumulating opposite charges (holes) so that the charges (electrons) desired to be read by the avalanche portion 720 pass through. The P- region 710 is preferably formed as a low concentration region so as to increase the potential in the middle so that the charges pass through the avalanche portion 720.

[0127] The N+ region 740 is connected to the electrode 102 via the N+ region 750. An N- region 780 is formed on the side of the P+ region 730 and the N+ region 740. A P+ layer 790 is provided, which is electrically connected to the N+ region 740 and the N- region 780. The P+ layer 790 is grounded (GND) via the electrode 800. The P+ layer 790 may be an N layer. Electrodes such as the wiring layer 820 connected to the P+ layer 790 may not be formed. The electrode 102 is an electrode that outputs a signal corresponding to the incident light. On the other hand, the electrode 800 is an electrode for discharging holes. The P+ layer 790 and the electrode 800 may not be provided. The electrode 102, the electrode 800, and the buried metal layer 190 provided in the pixel separation unit 150 are each connected to the wiring layer 820. The wiring layer 820 is Fig.18 The uppermost wiring layer of the wiring layers shown is a portion of the wiring layer. The P+ layer 790 may be an N layer. Electrodes such as the wiring layer 820 connected to the P+ layer 790 may not be provided.

[0128] An insulating film (fixed charge film) 810 is provided on the side of the pixel separation unit 150 and the upper layer of the P region 760. For example, the insulating film 810 is negatively charged. The structure of the upper layer of the P region 760 is similar to Fig.18 The construction shown is essentially the same. Fig.21A In the illustrated structure, the imaging device 1000 can be configured by interchanging the P-type and N-type conductivity types.

[0129] exist Fig.21A In the imaging device 1000 having the aforementioned structure, the N+ region 740 and the N+ region 750 correspond to Figure 2 The N-type layer 180 shown, the P region 760 , the P region 700 , and the P− region 710 correspond to the photoelectric conversion portion (third semiconductor layer) 160 and the P-type layer 170 .

[0130] In each of the modified examples described below, it is assumed that the Fig.21AThe structure of the SPAD pixel shown in the figure is omitted as appropriate. In each modification example, although a structure other than the basic structure is partially shown, it can be replaced by the basic structure as appropriate. Fig. 21B is a schematic cross-sectional view showing an example in which the metal layer 152 is connected to Fig.18 The insulating film is covered with the same insulating layer 200, and is provided with Fig.21A The color filters 300a, 300b and 300c in FIG.

[0131] 8.2. First Modification

[0132] like Figure 3 As shown, by burying the buried metal layer 190 in the pixel separation unit 150, the light shielding between adjacent pixels can be improved, so that the inter-pixel interference occurring in the deeper area of ​​the pixel area can be suppressed. The first modification example relates to a configuration in which the anode electrode 130 is used as the metal layer 152, and the buried metal layer 190 and the anode electrode 130 (metal layer 152) are electrically connected.

[0133] Fig.22A 1 is a schematic cross-sectional view showing in detail the vicinity of the pixel separation unit 150 of the image pickup device 1000 according to the first modification. Fig.22A As shown, the buried metal layer 190 is provided to penetrate the pixel separation portion 150. The buried metal layer 190 is electrically connected to the P region 760 on the back side via the metal layer 152. By electrically connecting the buried metal layer 190 to the metal layer 152 used as the anode electrode 130, the parasitic resistance of the anode electrode can be reduced. In particular, the voltage drop in the middle part of the pixel region can be reduced.

[0134] FIG. 22B to FIG. 22H is a schematic cross-sectional view showing other aspects of the imaging device 1000 according to the first modification. FIG. 22B to FIG. 22H In various aspects, buried metal layer 190 and metal layer 152 are electrically connected.

[0135] Fig. 22B An example is shown in which the pixel separation portion 150 is covered with the metal layer 152 . Fig. 22C An example is shown in which no Fig.22A The insulating film 510 is buried on the front surface side shown, and the width of the pixel separation portion 150 read from the rear surface to the front surface is constant. Fig.22D An example is shown in which Fig.22A The buried insulating film 510 is shown to be recessed to form a concave portion 520 ′, and a buried metal layer 530 connected to the buried metal layer 190 is formed in the concave portion 520 ′. Fig.22E It shows that Fig.22AThe structure shown is a schematic diagram of an example in which a buried metal layer 190 is formed but an insulating film 194 is not provided. Fig.22E In the illustrated structure, although the upper end surface of the buried metal layer 190 protrudes further than the upper surface of the insulating film 810 , the upper end surface of the buried metal layer 190 may be located at the same position as the upper surface of the insulating film 810 . Fig.22F It shows that Fig.22A The structure shown is a structure in which the buried metal layer 190 is not connected to the wiring layer 820 . Figure 22G It shows that Fig.22A The illustrated configuration is a configuration in which the insulating film 810 extends to the lower portion of the buried insulating film 510 . Fig.22H It shows that Fig.22A The structure shown in the figure is a structure in which a high concentration P layer 830 is provided on the side of the buried metal layer 190 and an insulating film 810 is not provided. The high concentration P layer 830 corresponds to the structure described below. Fig.25 The P layer 544 shown in the manufacturing process. Fig.22H As shown in FIG. 8 , a high concentration P layer 830 may be formed instead of the insulating film 810. Fig.22H In the embodiment, the insulating film 810 formed on the P region 760 may not be provided.

[0136] exist FIG. 22A to FIG. 22C , Fig.22E , Figure 22G and Fig.22H In the embodiment, the buried metal layer 190 is connected to the wiring layer 820 located on the opposite side of the metal layer 152. By connecting the buried metal layer 190 to the wiring layer 820, the area used as the anode wiring can be expanded and the resistance of the anode can be further reduced.

[0137] By connecting the buried metal layer 190 to the wiring layer 820, color mixing due to leakage of light in adjacent pixels can be further suppressed. By connecting the wiring layer 820 extending in the horizontal direction or the wiring layer 820 formed deeper than the substrate to the buried metal layer 190, the incidence of light to adjacent pixels due to reflection from the wiring layer 820 of the lower layer can be suppressed. The wiring layer 820 in the horizontal direction connected to the buried metal layer 190 can reflect obliquely incident light and make the light incident again on the pixel desired to be detected.

[0138] It is also possible to discharge charges (holes collected by the P type) on the incident surface side (upper side) of light, and it is also possible to discharge charges from the lower side or from both the upper side and the lower side when connected to the wiring layer 820 on the lower side. In a plan view, the wiring layer 820 on the lower side can also be arbitrarily formed similarly to the wiring layout on the upper side.

[0139] FIG. 23A to FIG. 23G1 is a plan view showing an image pickup device 1000 according to a first modification. Fig.23A In the example shown, the metal layer 152 is formed along the pixel separation portion 150 to have a greater width than the buried metal layer 190 and corresponds to Fig.22A The structure of FIG. 23A to FIG. 23G , the region of the metal layer 152 is indicated by dots, and a portion C in which the metal layer 152 is electrically connected to the P region 760 is shown. Fig.23A The illustrated example shows a configuration in which a portion C of the metal layer 152 electrically connected to the P region 760 is formed at each of four locations of one pixel. Fig. 23B The example shown shows a configuration in which Fig.22A In the configuration of FIG. 7 , a portion C of the metal layer 152 electrically connected to the P region 760 is formed at one position of one pixel. Fig.23C The example shown shows a configuration in which Fig.22A In the structure of FIG. 1 , a portion C of the metal layer 152 electrically connected to the P region 760 is disposed on four sides along the buried metal layer 190 , and the portion C of the metal layer 152 electrically connected to the P region 760 is formed in a ring shape. Fig.23C In the embodiment, a portion C in which the metal layer 152 is electrically connected to the P region 760 may be formed only on one side along the buried metal layer 190 . Fig.23D The example shown corresponds to Fig. 22B The structure of Fig.23D In the example shown, Fig.23A As in the embodiment, a metal layer 152 having a width greater than that of the buried metal layer 190 is formed along the pixel separation portion 150 , and a portion C electrically connected to the P region 760 is formed in each of the four corners of the pixel and adjacent to the buried metal layer 190 . Fig.23E The example shown shows that Fig.23D A configuration in which a portion C electrically connected to the P region 760 is provided at one position of one pixel. Fig.23F The example shown shows that Fig.23D The planar shape of the portion C electrically connected to the P region 760 is a triangular configuration. Fig.23F The structure can further widen the opening for light incidence of the metal layer 152. The planar shape of the portion C electrically connected to the P region 760 may be a shape other than a triangle, and may be a circle, for example. Figure 23G The example shown is Fig.23D Schematic diagram of an example in which the portion C electrically connected to the P region 760 is arranged along the buried metal layer 190. Figure 23G In the embodiment, the portion C in which the metal layer 152 is electrically connected to the P region 760 may be formed only on one side along the buried metal layer 190. FIG. 23A to FIG. 23GIn the planar structure, the metal layer 152 does not protrude toward the photoelectric conversion portion side relative to the pixel separation portion 150 except for a portion C electrically connected to the P region 760 .

[0140] In the following, reference will be made to Fig.24 A method for manufacturing a semiconductor device according to the first modification example will be described in order of steps. Fig.24 Schematic cross-sectional views showing a method for manufacturing a semiconductor device according to a first modification example in order of steps.

[0141] First, in process (1), necessary N layer and P layer are formed on Si substrate 520 by ion implantation or heat treatment, etc., and a desired structure is formed by deposition to form a first layer 528 in which an insulating film of a buried insulating film is buried and surrounds the pixel. Thus, Fig.21A The N regions and P regions shown. Fig.24 , each N region and each P region are not shown. Then, by forming a metal layer 530 on the first layer 528 in which the insulating film is buried and further forming an insulating film, the metal layer 530 is buried in the first layer 528. Various changes in the burying of the first layer 528 can be considered, such as an oxide film, a nitride film, or a stacked structure of an oxide film and a nitride film. The metal layer 530 is preferably formed of tungsten (W). The metal layer 530 may not be formed.

[0142] Subsequently, in process (2), the necessary wiring layers are formed, and then the front and rear surfaces are inverted by a scheme such as lamination, and unnecessary layers are removed. Subsequently, in process (3), the Si substrate 520 is etched to reach the buried insulating layer, and then an insulating film 532 formed of aluminum oxide (Al2O3) or hafnium oxide (HfO2), etc. and an insulating film 534 formed of an oxide film, etc. are formed. When forming these films, it is preferred to use a film type with good coverage. Then, in process (4), a groove (groove) is formed that penetrates the first buried layer 528 and reaches the metal layer 530, and a metal layer 536 is buried. The metal layer 536 is preferably formed of tungsten (W) or the like. After penetrating the Si layer 526 and the first buried layer 528, insulating films 532 and 534 can be formed, and the metal layer 536 can be buried. Finally, in process (5), after forming the insulating layer 200, an electrode 538 with a back contact is formed. Through these processes, an element including a back electrode is manufactured. The N layer and the P layer may be reversed. In this case, the type of the insulating film 532 is changed. Then, a layer is formed on the insulating layer 200 and the electrode 538. Fig.21A The color filters 300a, 300b and 300c and the on-chip lens 400 ( Fig.24 not shown).

[0143] exist Fig.24In the manufacturing method shown, when the insulating film 532 is not formed, the second buried layer formed from the front side to the back side can be surrounded by a high concentration P layer using solid phase diffusion or the like when forming the front surface side. Fig.25 is a schematic diagram showing the manufacturing process in this case. In process (1), necessary N layer and P layer are formed on Si substrate 520 by ion implantation or heat treatment, etc., and the desired structure is formed by deposition. In this way, Fig.21A Then, the second layer 540 is buried in the Si substrate 520, and the metal layer 542 is buried in the second layer 540. When the second layer 540 is buried, a high concentration P layer 544 is formed on the Si substrate 520 adjacent to the second layer 540 by solid phase diffusion or the like.

[0144] Then, in process (2), the front and rear surfaces are inverted and unnecessary layers are removed. Thereafter, after a predetermined insulating film is formed on the Si substrate 520, as shown in FIG. Fig.24 As in the process (5) of the present invention, an electrode 538 having a back contact is formed. Then, a Fig.21A The color filters 300a, 300b and 300c and the on-chip lens 400 ( Fig.24 not shown).

[0145] exist Fig.24 and Fig.25 In the process diagram shown, the insulating film 532 corresponds to FIG. 22A to FIG. 22F The insulating film 810 in the metal layer 536 corresponds to FIG. 22A to FIG. 22F The buried metal layer 190 in the electrode 538 corresponds to the metal layer 152 (anode electrode). The buried metal layer 190 and the metal layer 152 may be formed of the same material, and can be formed of a metal such as tungsten (W).

[0146] According to the first modification, the metal layer 152 used as the anode electrode 130 is electrically connected to the P region 760 of the photoelectric conversion unit 160, so the parasitic resistance of the anode wiring can be reduced. The metal layer 152 used as the anode electrode 130 is electrically connected to the P region 760 of the photoelectric conversion unit 160, so the voltage drop in the middle part of the pixel area can be reduced.

[0147] 8.3. Second Modification

[0148] In the first modification, as shown in FIG23, the metal layer 152 (anode electrode) connected to the P region 760 is formed along the pixel separation portion 150. Therefore, the contact area between the P region 760 and the metal layer 152 can be sufficiently ensured, so the contact resistance between the P region 760 and the metal layer 152 can be reduced. On the other hand, in the case of this configuration, due to the wiring layer 500 formed inside the pixel separation portion 150, the photoelectric conversion portion of each pixel is reduced.

[0149] In the second modification, as in the first modification, the buried metal layer 190 is electrically connected to the metal layer 152. By digging out the P region 760 in the connection portion between the metal layer 152 and the P region 760, the contact area is increased, so the contact resistance can be reduced. When the occupied area of ​​the wiring layer 500 inside the pixel separation unit 150 is suppressed to the extent of increasing the contact area by digging out the P region 760 and the maximum area of ​​the photoelectric conversion unit of each pixel is ensured, the sensitivity of the imaging device 1000 can be further improved without increasing the contact resistance.

[0150] Fig.26 is a schematic cross-sectional view showing an image pickup device 1000 in a second modification. Fig.26 In the embodiment, the excavated area of ​​the P region 760 is filled with the contact portion 152a of the metal layer 152 connected to the P region 760. Therefore, since the contact area is also formed on the side wall of the contact portion 152a, the contact area is increased, so that the contact resistance can be reduced. The excavated area of ​​the P region 760 is considered to be any one of a variety of shapes such as a groove shape, a hole shape, or a shape connected to a groove engraved between pixels. In the planar structure, the metal layer 152 does not protrude toward the photoelectric conversion portion compared to the pixel separation portion 150, except for the area where the contact portion 152a is formed. By further increasing the length of the contact portion 152a, the contact area between the contact portion 152a and the P region 760 is increased, so the contact resistance can be reduced.

[0151] According to the second modification, by connecting the metal layer 152 to the P region 760 using the contact portion 152 a , it is possible to ensure a larger area for the photoelectric conversion portion.

[0152] 8.4. Third Modification

[0153] In the third modification, when the metal layer 152 connected to the buried metal layer 190 is connected to the P region 760 , the contact resistance between the metal layer 152 and the P region 760 is reduced by retreating the insulating film 810 of the pixel separation unit 150 .

[0154] Fig. 27 is a schematic cross-sectional view showing an image pickup device 1000 according to a third modification. Fig. 27In the illustrated configuration, the insulating film 810 is formed along the insulating film 194 of the pixel separation portion 150 . The upper end of the insulating film 810 along the pixel separation portion 150 is retreated to a position lower than the upper end of the insulating film 194 of the pixel separation portion 150 . Fig. 27 The illustrated distance d1 indicates the retreat amount in the downward direction of the insulating film 810 .

[0155] Fig.28 It is shown Fig. 27 FIG. 1 is a schematic diagram of an enlarged range of the region A1 shown in FIG. 1 , and shows the state before and after the metal layer 152 is filled. Fig.28 , the vicinity of the insulating film 810 is shown in more detail. The insulating film 192 and the film 193 formed of tantalum oxide (Ta2O5) or the like are formed adjacent to the insulating film 810. Since the film 193 is formed by a sputtering method, the coverage is relatively low, and the film 193 is not formed on the side wall of the groove 701. On the other hand, since the insulating film 192 is formed by CVD or the like, the coverage is good, and the insulating film 192 is also formed on the side wall of the groove 701. Fig.28 The state before the metal layer 152 is filled shown on the left side of FIG. 1 is a state in which a groove 701 filled with the buried metal layer 190 is formed in the pixel separation portion 150, and an opening 702 is formed in the upper portion of the pixel separation portion 150. In this case, the groove 701 is not filled with the buried metal layer 190, and the opening 702 is not filled with the metal layer 152. Fig.28 The dotted line shown indicates the range of the opening 702 before the insulating film 810 is retreated. After the opening 702 is formed within the range indicated by the dotted line, the insulating film 810 is retreated by a cleaning process. The insulating film 810 retreats by a distance d1 in the vertical direction and by a distance d2 in the horizontal direction. For example, the retreat amount is about several nanometers to several tens of nanometers.

[0156] Thereafter, as shown in the filled state, Fig.28 As shown on the right side of , buried metal layer 190 is formed to fill groove 701, and metal layer 152 is formed to fill opening 702. Therefore, the area of ​​metal layer 152 connected to P region 760 is extended to the extent that insulating film 810 is retreated, and thus, the contact resistance between P region 760 and metal layer 152 can be reduced. Fig. 27 and Fig.28 In the example shown, the metal layer 152 and the buried metal layer 190 may be integrated.

[0157] As described above, by making the insulating film 810 retreat, the contact area between the P region 760 and the metal layer 152 can be expanded. Fig. 27 The structure of the third variation example shown can further reduce the contact resistance between the P region 760 and the metal layer 152 .

[0158] Fig.29 is a schematic cross-sectional view showing another example of the third modification. Fig.29 In the illustrated configuration, the metal layer 152 is brought into contact with the P region 760 at a position separated from the pixel separation portion 150 .

[0159] Fig.30 It is shown Fig.29 A schematic diagram of an enlarged range of area A2 is shown. Fig.30 The dashed line shows the range of the opening 704 before the insulating film 810 is retreated. After the opening 704 is formed within the range shown by the dashed line, the insulating film 810 is retreated in the horizontal direction by a distance d2 through a cleaning process.

[0160] Thereafter, the metal layer 152 is formed to fill the opening 704. Therefore, the region where the metal layer 152 contacts the P region 760 is expanded to such an extent that the insulating film 810 recedes in the horizontal direction, and thus the contact resistance between the metal layer 152 and the P region 760 can be reduced.

[0161] In the following, reference will be made to Fig.31 The method for manufacturing a semiconductor device according to the third modification example will be described in process order. Fig.31 Schematic cross-sectional views showing a method for manufacturing a semiconductor device according to a third modification example in process order.

[0162] In executing Fig.24 After the same process as (1) and (2), Fig.31 In the process (4), the Si layer 926 is etched to reach the buried insulating film, and then an insulating film 810 formed of aluminum oxide (Al2O3) or hafnium oxide (HfO2) and the like and an insulating film 934 formed of an oxide film and the like are formed. When forming these films, it is preferable to use a film type having good coverage.

[0163] Then, in step (5), the first buried layer 928 is penetrated and a groove reaching the metal layer 930 is formed. In addition, in step (5), after the opening 702 is formed, cleaning is performed. Fig.28 As shown, the insulating film 810 retreats in the downward direction and the horizontal direction. For example, when the insulating film 810 is formed of aluminum oxide (Al2O3) or hafnium oxide (HfO2), etc., the insulating film 810 is retreated by about several nanometers to tens of nanometers using inorganic chemicals such as DHF or general organic chemicals for post-process cleaning.

[0164] Subsequently, in process (6), a metal layer 936 is buried. The metal layer 936 is preferably formed of tungsten (W) or the like. Sputtering or chemical vapor deposition (CVD) or the like can be used as a method for forming a metal film, but CVD is advantageous for covering. Therefore, the region including the inside of the groove and the inside of the opening 702 formed in step (5) is filled with the metal layer 936. The portion where the insulating film 810 is retreated is also filled with the metal layer 936. The filled metal layer 936 corresponds to the buried metal layer 190 and the metal layer 152. The P layer 924 corresponds to Fig. 27 Thereafter, the P region 760 is formed. Fig.21A The color filters 300a, 300b and 300c and the on-chip lens 400 ( Fig.31 not shown).

[0165] As described above, in the cleaning process of step (5), the insulating film 810 is retreated in the downward direction and the horizontal direction. Then, since the portion of the insulating film 810 retreated by filling the metal layer 936 in process (6) is filled with the metal layer 936, the contact area between the metal layer 936 and the P region 760 increases, so that the contact resistance can be reduced. Fig.29 In the case of the structure shown, the opening 704 can be formed at a position separated from the pixel separation unit 150 in step (5).

[0166] Fig.32 is a schematic cross-sectional view showing such an example, wherein when Fig.31 In step (5), when the insulating film 810 formed in the first buried layer 928 in the groove retreats, an insulating film is further formed in the groove.

[0167] Fig.33 It is shown Fig.32 The cross-sectional view of the enlarged region A3 in the step (5-1) and the step (5-2) shown in FIG. By forming a groove penetrating the first buried layer 928 and reaching the metal layer 930, and then performing a cleaning process, the insulating film 810 is exposed on the first buried layer 928. Therefore, as Fig.33 As shown in the left figure of FIG. 8 , the insulating film 810 retreats on the first buried layer 928. Since the withstand voltage of the pixel separation unit 150 may be reduced due to this retreat, Fig.32 In the process (5-2), an insulating film 950 is formed in the contact hole, and the insulating film 810 exposed in the contact hole on the first buried layer 928 is covered by the insulating film 950. At this time, it is suitable to form the insulating film 950 with a high withstand voltage by a scheme such as atomic layer deposition (ALD). Fig.33As shown in the right figure of FIG. 8 , the insulating film 810 is covered with the insulating film 950 on the first buried layer 928. By etching back by dry etching or the like, the insulating film 950 of the portion where the insulating film 810 retreats remains, and the unnecessary portion of the insulating film can be removed.

[0168] Thereafter, in step (5-3), by forming an opening 702 and performing a cleaning process, as shown in FIG. Fig.31 As in step (5) shown in FIG. 1 , the insulating film 810 is made to retreat downward and horizontally. Fig.31 The process is the same.

[0169] As described above, according to the third modification, by making the insulating film 810 retreat, the contact area between the metal layer 152 and the P region 760 can be increased, and the contact resistance can be reduced. Fig.32 and Fig.33 As shown, by retreating the insulating film 810 on the side wall of the pixel separation portion 150 other than the contact portion and burying the insulating film, the withstand voltage can be improved.

[0170] 9. Application examples other than imaging devices

[0171] For example, the present disclosure can also be applied to other devices that detect light, such as a time-of-flight (TOF) sensor. In the case of being applied to a TOF sensor, for example, it can be applied to a distance image sensor according to a direct TOF measurement method or a distance image sensor according to an indirect TOF measurement method. In a distance image sensor according to a direct TOF measurement method, a light pulse with a short pulse width is sent and an electric pulse is generated by a high-speed response receiver to obtain the arrival time of photons in the direct time region of each pixel. At this time, the present disclosure can be applied to the receiver. In the indirect TOF method, a semiconductor element structure is used to measure the light flight time, in which the amount of carriers generated by the light that are detected and accumulated is changed according to the light arrival time. The present disclosure can also be used as the semiconductor structure. In the case of being applied to a TOF sensor, arbitrarily setting Fig.18 The color filters 300a, 300b, and 300c and the on-chip lens 400 are shown, but these components may not be provided.

[0172] 10. Example of electronic device construction

[0173] Fig.34 is a schematic diagram showing a configuration of an electronic device 3000 including the above-described imaging device 1000 . Fig.34The electronic device 3000 shown includes: a first semiconductor chip 3100, which includes a sensor unit 3010, in which a plurality of photoelectric conversion units 160 are provided; and a second semiconductor chip 3200, which includes a signal processing unit 3020, which processes the signal acquired by the photoelectric conversion unit 160. The first semiconductor chip 3100 and the second semiconductor chip 3200 are stacked. A control unit 3030 and a storage unit 3040 are provided, and the control unit 3030 is located near the signal processing unit 3020 and controls the electronic device 3000, and the storage unit 3040 stores the signal acquired by the photoelectric conversion unit 160. For example, in addition to the control of the signal processing unit 3020, the control unit 3030 can also be arranged for other drives or controls near the photoelectric conversion unit 160. In addition to the illustrated arrangement, the control unit 3030 can also have any function in any area of ​​the first semiconductor chip 3100 and the second semiconductor chip 3200. The plurality of photoelectric conversion units 160 are arranged in a two-dimensional matrix state (matrix form). In Fig.34 , for convenience of explanation, the first semiconductor chip 3100 and the second semiconductor chip 3200 are shown in a separated state.

[0174] 11. Application examples for mobile objects

[0175] The technology of the present disclosure (the present technology) can be applied to various products. For example, the technology of the present disclosure can be implemented as a device installed on any type of mobile body, such as: a car, an electric car, a hybrid car, a motorcycle, a bicycle, a personal mobile device, an airplane, a drone, a ship, and a robot.

[0176] Fig.35 : is a block diagram showing a schematic configuration example of a vehicle control system as an example of a moving body control system to which the technology of the present disclosure can be applied.

[0177] The vehicle control system 12000 includes a plurality of electronic control units connected to each other via a communication network 12001. Fig.35 In the example shown, the vehicle control system 12000 includes a drive system control unit 12010, a body system control unit 12020, an external information detection unit 12030, an internal information detection unit 12040, and an integrated control unit 12050. As a functional configuration of the integrated control unit 12050, a microcomputer 12051, a sound and image output unit 12052, and an in-vehicle network interface (I / F: Interface) 12053 are shown.

[0178] The drive system control unit 12010 controls the operation of the devices related to the drive system of the vehicle according to various programs. For example, the drive system control unit 12010 functions as a control device for the following devices: a drive force generating device such as an internal combustion engine or a drive motor for generating the drive force of the vehicle; a drive force transmitting mechanism for transmitting the drive force to the wheels; a steering mechanism for adjusting the steering angle of the vehicle; and a braking device for generating the braking force of the vehicle.

[0179] The body system control unit 12020 controls the operation of various devices installed in the vehicle body according to various programs. For example, the body system control unit 12020 functions as a control device for the following devices: a keyless entry system; a smart key system; a power window device; or various lights such as headlights, taillights, brake lights, turn signal lights, and fog lights. In this case, it is possible to input radio waves sent from a portable device that replaces the key or signals of various switches to the body system control unit 12020. The body system control unit 12020 receives the input of the radio waves or signals, and controls the door lock device, power window device, and lights of the vehicle.

[0180] The vehicle exterior information detection unit 12030 detects the exterior information of the vehicle on which the vehicle control system 12000 is installed. For example, the camera unit 12031 is connected to the vehicle exterior information detection unit 12030. The vehicle exterior information detection unit 12030 causes the camera unit 12031 to capture an image of the exterior of the vehicle and receives the captured image. Based on the received image, the vehicle exterior information detection unit 12030 can perform object detection processing or distance detection processing on pedestrians, vehicles, obstacles, signs, text on the road surface, and the like.

[0181] The imaging unit 12031 is an optical sensor for receiving light and outputting an electrical signal according to the amount of received light. The imaging unit 12031 can output the electrical signal as an image, or can output the electrical signal as distance measurement information. The light received by the imaging unit 12031 may be visible light, or may be non-visible light such as infrared rays.

[0182] The in-vehicle information detection unit 12040 detects information about the interior of the vehicle. For example, a driver state detection unit 12041 for detecting a driver state is connected to the in-vehicle information detection unit 12040. For example, the driver state detection unit 12041 includes a camera for photographing the driver. Based on the detection information input from the driver state detection unit 12041, the in-vehicle information detection unit 12040 can calculate the driver's fatigue level or concentration level, or can determine whether the driver is dozing off.

[0183] The microcomputer 12051 can calculate the control target value of the driving force generating device, the steering mechanism or the braking device based on the information outside and inside the vehicle obtained by the vehicle outside information detection unit 12030 or the vehicle inside information detection unit 12040, and can output a control command to the driving system control unit 12010. For example, the microcomputer 12051 can perform cooperative control for realizing the functions of the advanced driver assistance system (ADAS), which includes: collision avoidance, impact mitigation, following driving based on vehicle-to-vehicle distance, speed maintenance driving, collision warning of the vehicle or lane departure warning of the vehicle.

[0184] The microcomputer 12051 can control the driving force generating device, steering mechanism, braking device, etc. based on the information near the vehicle obtained by the external information detection unit 12030 or the internal information detection unit 12040, thereby performing collaborative control for automatic driving for autonomous driving without the need for driver operation.

[0185] Based on the information outside the vehicle acquired by the vehicle exterior information detection unit 12030, the microcomputer 12051 can output a control command to the body system control unit 12020. For example, the microcomputer 12051 can control the headlights according to the position of the preceding vehicle or the oncoming vehicle detected by the vehicle exterior information detection unit 12030, thereby performing cooperative control for achieving anti-glare, such as switching from high beam to low beam.

[0186] The sound and image output unit 12052 sends an output signal of at least one of sound and image to an output device, which can visually or auditorily notify information to passengers on the vehicle or outside the vehicle. Fig.35 In the example of FIG. 1 , as output devices, an audio speaker 12061, a display unit 12062, and an instrument panel 12063 are illustrated. For example, the display unit 12062 may include at least one of an on-board display and a head-up display.

[0187] Fig.36 12031 is an explanatory diagram showing an example of the installation position of the imaging unit 12031.

[0188] exist Fig.36 In the figure, the camera unit 12031 includes camera units 12101, 12102, 12103, 12104 and 12105.

[0189] The camera units 12101, 12102, 12103, 12104 and 12105 are provided at the following positions, for example, the front nose, side mirrors, rear bumper, trunk door and the upper part of the windshield in the vehicle compartment of the vehicle 12100. The camera unit 12101 provided at the front nose and the camera unit 12105 provided at the upper part of the windshield in the vehicle compartment mainly acquire the front image of the vehicle 12100. The camera units 12102 and 12103 provided on the side mirrors mainly acquire the side image of the vehicle 12100. The camera unit 12104 provided on the rear bumper or trunk door mainly acquires the rear image of the vehicle 12100. The camera unit 12105 provided at the upper part of the windshield in the vehicle compartment is mainly used to detect the preceding vehicle or pedestrians, obstacles, traffic lights, traffic signs and lanes, etc.

[0190] Fig.36 An example of the imaging ranges of the imaging units 12101 to 12104 is shown. The imaging range 12111 is the imaging range of the imaging unit 12101 provided on the front nose, the imaging ranges 12112 and 12113 are the imaging ranges of the imaging units 12102 and 12103 provided on the side mirrors, respectively, and the imaging range 12114 is the imaging range of the imaging unit 12104 provided on the rear bumper or the trunk door. For example, by superimposing the image data captured by the imaging units 12101 to 12104, a bird's-eye view image of the vehicle 12100 viewed from above can be obtained.

[0191] At least one of the imaging units 12101 to 12104 may have a function of acquiring distance information. For example, at least one of the imaging units 12101 to 12104 may be a stereo camera including a plurality of imaging elements, or may be an imaging element having pixels for phase difference detection.

[0192] For example, the microcomputer 12051 can obtain the distance to each three-dimensional object within the imaging range 12111 to 12114 and the change of the distance over time (relative speed relative to the vehicle 12100) based on the distance information obtained from the imaging units 12101 to 12104, thereby extracting the three-dimensional object that is closest to the vehicle 12100 on the road and traveling at a predetermined speed (for example, greater than or equal to 0 km / h) in the same direction as the vehicle 12100 as the leading vehicle. In addition, the microcomputer 12051 can set the inter-vehicle distance to be maintained in front of the leading vehicle in advance, and can perform automatic braking control (also including follow-up stop control) or automatic acceleration control (also including follow-up start control). In this way, cooperative control for realizing automatic driving and the like that can be performed without the need for driver operation can be performed.

[0193] For example, based on the distance information obtained from the camera units 12101 to 12104, the microcomputer 12051 can classify the three-dimensional object data related to the three-dimensional object into three-dimensional object data of other three-dimensional objects such as two-wheeled vehicles, ordinary vehicles, large vehicles, pedestrians and electric poles, extract the classified three-dimensional object data, and then use the extracted three-dimensional object data to automatically avoid obstacles. For example, the microcomputer 12051 identifies obstacles around the vehicle 12100 as obstacles that can be recognized by the driver of the vehicle 12100 and obstacles that are difficult to recognize. Then, the microcomputer 12051 determines the collision risk used to represent the risk of collision with each obstacle. When the collision risk is greater than or equal to the set value and there is a possibility of collision, it is possible to output a warning to the driver through the audio speaker 12061 or the display unit 12062 or perform forced deceleration or avoidance steering through the drive system control unit 12010 to perform driving assistance for avoiding collision.

[0194] At least one of the camera units 12101 to 12104 may be an infrared camera that detects infrared rays. For example, the microcomputer 12051 is capable of identifying pedestrians by determining whether there are pedestrians in the images captured by the camera units 12101 to 12104. For example, pedestrians are identified by the following process: a process of extracting feature points in the images captured by the camera units 12101 to 12104 as infrared cameras; and a process of determining whether the object is a pedestrian by pattern matching a series of feature points representing the contour of the object. When the microcomputer 12051 determines that there are pedestrians in the images captured by the camera units 12101 to 12104 and identifies the pedestrians, the sound and image output unit 12052 controls the display unit 12062 so that a rectangular contour line for emphasizing the identified pedestrian is superimposed and displayed. The sound and image output unit 12052 may control the display unit 12062 so that an icon or the like for representing a pedestrian is displayed at a desired position.

[0195] An example of a vehicle control system to which the technology according to the present disclosure is applied has been described above. The technology according to the present disclosure can be applied to the camera unit 12031 and the like in the above-described configuration.

[0196] 12. Application examples of endoscopic surgery systems

[0197] The technology according to the present disclosure (the present technology) can be applied to various products. For example, the technology according to the present disclosure can be applied to an endoscopic surgery system.

[0198] Fig.37 is a diagram showing a schematic configuration example of an endoscopic surgery system to which the technology according to the present disclosure (the present technology) can be applied.

[0199] Fig.37 The figure shows a situation where a surgical staff (doctor) 11131 is using an endoscopic surgery system 11000 to perform surgery on a patient 11132 on a bed 11133. As shown in the figure, the endoscopic surgery system 11000 includes: an endoscope 11100; other surgical tools 11110 such as a pneumoperitoneum tube 11111 or an energy treatment tool 11112; a support arm device 11120 supporting the endoscope 11100; and a cart 11200 on which various devices for endoscopic surgery are mounted.

[0200] The endoscope 11100 includes: a barrel 11101, a region having a predetermined length from the distal end of the barrel 11101 is inserted into a body cavity of a patient 11132; and a camera 11102 connected to the proximal end of the barrel 11101. In the illustrated example, although the endoscope 11100 constructed as a so-called rigid scope having a hard barrel 11101 is illustrated, the endoscope 11100 may also be constructed as a so-called flexible scope including a flexible barrel.

[0201] At the far end of the lens barrel 11101, an opening is provided, in which an objective lens is assembled. A light source device 11203 is connected to the endoscope 11100, and the light generated by the light source device 11203 is guided to the far end of the lens barrel 11101 through a light guide member extending in the lens barrel 11101, and the light irradiates the observation object in the body cavity of the patient 11132 through the objective lens. The endoscope 11100 can be a direct-viewing mirror, an oblique-viewing mirror, or a side-viewing mirror.

[0202] An optical system and an imaging element are provided inside the camera head 11102, and the light reflected from the observation object (observation light) is focused on the imaging element by the optical system. The observation light is photoelectrically converted by the imaging element, thereby generating an electrical signal corresponding to the observation light, that is, an image signal corresponding to the observation image. The image signal is sent to the camera control unit (CCU: Camera Control Unit) 11201 as raw data.

[0203] The CCU 11201 is composed of a central processing unit (CPU) or a graphics processing unit (GPU), etc., and integrally controls the operations of the endoscope 11100 and the display device 11202. In addition, the CCU 11201 receives an image signal from the camera 11102, and performs various image processing such as development processing (demosaic processing) on ​​the image signal to display an image based on the image signal.

[0204] Under the control of the CCU 11201 , the display device 11202 displays an image based on an image signal subjected to image processing in the CCU 11201 .

[0205] The light source device 11203 is constituted by, for example, a light source such as a light emitting diode (LED), and supplies irradiation light to the endoscope 11100 when photographing a surgical site or the like.

[0206] The input device 11204 is an input interface of the endoscopic surgery system 11000. The user can input various information or instructions to the endoscopic surgery system 11000 through the input device 11204. For example, the user inputs instructions for changing the imaging conditions of the endoscope 11100 (type of irradiation light, magnification, focal length, etc.).

[0207] The treatment tool control device 11205 controls the driving of the energy treatment tool 11112 for cauterizing or cutting tissues, or for sealing blood vessels, etc. The pneumoperitoneum device 11206 delivers gas to the body cavity of the patient 11132 through the pneumoperitoneum tube 11111 to expand the body cavity, thereby ensuring the field of view of the endoscope 11100 and ensuring the working space of the operating staff. The recorder 11207 is a device capable of recording various information related to the operation. The printer 11208 is a device capable of printing various information related to the operation in various formats (for example, text, images, or charts, etc.).

[0208] The light source device 11203 that provides irradiation light to the endoscope 11100 when photographing the surgical site can be composed of a white light source composed of, for example, an LED, a laser light source, or a combination of an LED and a laser light source. When the white light source is composed of a combination of RGB laser light sources, the output intensity and output timing of each color (each wavelength) can be controlled with high precision. Therefore, the light source device 11203 can adjust the white balance of the captured image. In this case, by irradiating the observed object with lasers from the RGB laser light sources in time sequence, and controlling the drive of the imaging element of the camera 11102 synchronously with the irradiation timing, images corresponding to RGB can also be captured in time sequence. According to this method, a color image can be obtained even if a color filter is not provided in the imaging element.

[0209] The drive of the light source device 11203 can be controlled to change the light intensity to be output at each predetermined time. By controlling the drive of the imaging element of the camera 11102 in synchronization with the timing of the change in light intensity and acquiring images in time sequence, and synthesizing the above images, a high dynamic range image without so-called black spots and white spots can be generated.

[0210] The light source device 11203 can be configured to provide light of a predetermined wavelength band corresponding to special light observation. In special light observation, for example, by utilizing the wavelength dependence of light absorption of human tissue, a narrower band of light than the irradiation light (i.e., white light) during ordinary observation is irradiated, thereby performing so-called narrow band imaging, and imaging predetermined tissues such as blood vessels in the surface layer of the mucosa with high contrast. Alternatively, in special light observation, an image can be obtained by fluorescence generated by irradiation with excitation light, thereby performing fluorescence observation. In fluorescence observation, for example, human tissue can be irradiated with excitation light, so that fluorescence from the human tissue can be observed (autofluorescence observation), or a reagent such as indocyanine green (ICG) can be locally injected into the human tissue, and the human tissue can be irradiated with excitation light corresponding to the fluorescence wavelength of the reagent, thereby obtaining a fluorescence image. The light source device 11203 can be configured to provide excitation light and / or narrow band light corresponding to special light observation.

[0211] Fig.38 It is shown Fig.37 A block diagram of an example of the functional configuration of the camera 11102 and the CCU 11201 shown.

[0212] The camera 11102 includes a lens unit 11401, an imaging unit 11402, a driving unit 11403, a communication unit 11404, and a camera control unit 11405. The CCU 11201 includes a communication unit 11411, an image processing unit 11412, and a control unit 11413. The camera 11102 and the CCU 11201 are communicably connected to each other via a transmission cable 11400.

[0213] The lens unit 11401 is an optical system, which is provided in a connection unit with the lens barrel 11101. Observation light received from the distal end of the lens barrel 11101 is guided to the camera head 11102 and is incident on the lens unit 11401. The lens unit 11401 is constructed as a combination of a plurality of lenses including a zoom lens and a focus lens.

[0214] The number of imaging elements constituting the imaging unit 11402 may be one (so-called single-chip), or may be multiple (so-called multi-chip). For example, when the imaging unit 11402 is constructed as a multi-chip imaging element, image signals corresponding to RGB, respectively, may be generated by each imaging element and a color image may be generated by synthesizing these image signals. Alternatively, the imaging unit 11402 may include a pair of imaging elements, which are used to respectively obtain an image signal for the right eye and an image signal for the left eye corresponding to a three-dimensional (3D) display. By performing a 3D display, the surgeon 11131 is able to more accurately grasp the depth of biological tissue in the surgical site. When the imaging unit 11402 is constructed as a multi-chip imaging element, a plurality of lens units 11401 are provided corresponding to each imaging element.

[0215] The camera unit 11402 does not have to be disposed in the camera head 11102. For example, the camera unit 11402 can be disposed in the lens barrel 11101 and immediately behind the objective lens.

[0216] The driving unit 11403 is composed of an actuator, and the driving unit 11403 moves the zoom lens and the focus lens of the lens unit 11401 by a predetermined distance along the optical axis under the control of the camera control unit 11405. In this way, the magnification and focus of the image captured by the camera unit 11402 can be appropriately adjusted.

[0217] The communication unit 11404 is constituted by a communication device for sending and receiving various information to and from the CCU 11201. The communication unit 11404 transmits the image signal obtained from the imaging unit 11402 to the CCU 11201 through the transmission cable 11400 as raw data.

[0218] The communication unit 11404 receives a control signal for controlling the driving of the camera 11102 from the CCU 11201, and provides the control signal to the camera control unit 11405. For example, the control signal includes information related to the imaging conditions, such as information for specifying the frame rate of the captured image, information for specifying the exposure value during imaging, and / or information for specifying the magnification and focus of the captured image.

[0219] The imaging conditions such as the aforementioned frame rate, exposure value, magnification, and focus may be appropriately specified by the user, or may be automatically set based on the acquired image signal by the control unit 11413 of the CCU 11201. In the latter case, the endoscope 11100 is equipped with a so-called automatic exposure (AE: auto exposure) function, an automatic focus (AF: autofocus) function, and an automatic white balance (AWB: auto white balance) function.

[0220] The camera control unit 11405 controls the driving of the camera 11102 based on the control signal from the CCU 11201 received through the communication unit 11404 .

[0221] The communication unit 11411 is composed of a communication device for transmitting and receiving various information to and from the camera 11102. The communication unit 11411 receives an image signal transmitted from the camera 11102 through the transmission cable 11400.

[0222] The communication unit 11411 transmits a control signal for controlling the driving of the camera 11102 to the camera 11102. The image signal or the control signal can be transmitted through electrical communication, optical communication, or the like.

[0223] The image processing unit 11412 performs various image processing on the image signal sent from the camera 11102 as raw data.

[0224] The control unit 11413 performs various controls related to imaging of a surgical site, etc., through the endoscope 11100 or display of an image obtained by imaging the surgical site, etc. For example, the control unit 11413 generates a control signal for controlling the driving of the camera head 11102.

[0225] Based on the image signal processed in the image processing unit 11412, the control unit 11413 causes the display device 11202 to display the captured image of the surgical site, etc. At this time, the control unit 11413 can use various image recognition technologies to identify various objects in the captured image. For example, the control unit 11413 can identify surgical tools such as forceps, specific biological sites, bleeding, or mist when using the energy treatment tool 11112, etc. by detecting the shape or color of the edge of the object included in the captured image. When the control unit 11413 causes the display device 11202 to display the captured image, the control unit 11413 can use the recognition result to superimpose various surgical auxiliary information on the image of the surgical site for display. By superimposing and displaying the surgical auxiliary information and presenting the surgical auxiliary information to the surgical staff 11131, the burden of the surgical staff 11131 can be reduced, or the surgical staff 11131 can be enabled to perform surgery safely.

[0226] The transmission cable 11400 connecting the camera head 11102 and the CCU 11201 together is an electrical signal cable corresponding to communication of electrical signals, an optical fiber corresponding to optical communication, or a composite cable corresponding to electrical communication and optical communication.

[0227] Here, in the example shown, although the transmission cable 11400 is used for wired communication, communication between the camera 11102 and the CCU 11201 may be performed in a wireless manner.

[0228] An example of an endoscopic surgery system to which the technology of the present disclosure can be applied has been described above. The technology according to the present disclosure can be applied to the endoscope 11100 or the imaging unit 11402 of the camera 11102 in the above-mentioned configuration.

[0229] Here, although the description has been made by taking the endoscopic surgery system as an example, the technology according to the present disclosure can also be applied to other technologies such as a microscope surgery system.

[0230] Although the preferred embodiments of the present disclosure have been described in detail, the technical scope of the present disclosure is not limited to the above examples. In the technical field of the present disclosure, it is obvious to those skilled in the art that various changes or corrections can be made within the scope of the technical spirit and essence described in the claims, and these changes and corrections are of course interpreted as belonging to the technical scope of the present disclosure.

[0231] For example, the chemical formulas described in the present specification are exemplary, and the chemical formulas may be changed.

[0232] The beneficial effects described in this specification are merely illustrative or exemplary and are not limiting. That is, in the technology according to the present disclosure, in addition to or in place of the aforementioned beneficial effects, other beneficial effects that are obvious to those skilled in the art and can be obtained from the description of this specification may also be achieved.

[0233] The following configurations belong to the technical scope of the present disclosure.

[0234] (1) A camera device comprising:

[0235] A first semiconductor layer formed on a semiconductor substrate;

[0236] a second semiconductor layer formed on the first semiconductor layer and having a conductivity type opposite to that of the first semiconductor layer;

[0237] a pixel separation unit configured to divide a pixel region including the first semiconductor layer and the second semiconductor layer;

[0238] a first electrode connected to the first semiconductor layer from one surface side of the semiconductor substrate; and

[0239] A metal layer is connected to the second semiconductor layer from a light irradiation surface side which is the other surface of the semiconductor substrate, and the metal layer is buried in the pixel separation portion in at least a portion in a thickness direction of the semiconductor substrate.

[0240] (2) The camera device described in (1), further comprising:

[0241] a second electrode connected to the second semiconductor layer from the light irradiation surface side and formed to correspond to the position of the pixel separation portion, wherein

[0242] The metal layer is electrically connected to the second semiconductor layer via the second electrode.

[0243] (3) The image pickup device described in (2), wherein the second electrode is formed along a periphery of the pixel region.

[0244] (4) The image pickup device described in (2), wherein the second electrode is formed in a region that is a part of a periphery of the pixel region.

[0245] (5) The image pickup device described in (4), wherein the second electrode is formed in at least one of four corners of the rectangular pixel area.

[0246] (6) The image pickup device described in (4) or (5), wherein the second electrode is buried in a hole formed in the second semiconductor layer.

[0247] (7) The image pickup device described in any one of (2) to (6), wherein the second electrode and the metal layer are formed of the same material.

[0248] (8) The image pickup device described in any one of (2) to (7), further including an insulating film formed along the pixel separation portion and the light irradiation surface, wherein:

[0249] The second electrode is embedded in an opening provided in the second semiconductor layer.

[0250] A region is provided where the end of the insulating film is set back from the wall surface of the opening, and

[0251] The region is filled with the second electrode.

[0252] (9) The imaging device described in any one of (1) to (8), further comprising an insulating film formed along the pixel separation portion, wherein:

[0253] A region in which an end portion of the insulating film recedes in the thickness direction of the pixel separating portion is formed and is filled with the insulating film.

[0254] (10) The image pickup device described in (2), wherein a voltage for multiplying electrons is applied between the first electrode and the metal layer.

[0255] (11) The image pickup device described in any one of (1) to (10), further including a third semiconductor layer formed on the second semiconductor layer and having the same conductivity type as the second semiconductor layer.

[0256] (12) The image pickup device described in (2), wherein the second electrode is provided on an upper surface of the pixel separation portion.

[0257] (13) The image pickup device described in (2), wherein the pixel separation portion and the second electrode have a planar shape of a grid shape surrounding the plurality of pixel areas.

[0258] [reference numerals list]

[0259] 100 cathode electrode (second electrode)

[0260] 130 anode electrode (first electrode)

[0261] 132 auxiliary electrode

[0262] 140 Contact layer

[0263] 150 Pixel Separation

[0264] 152 Metal Layer

[0265] 160 Photoelectric conversion unit (third semiconductor layer)

[0266] 170P type layer (second semiconductor layer)

[0267] 180N type layer (first semiconductor layer)

[0268] 190 buried metal layer

[0269] 760 P area

Claims

1. A camera device, comprising: A first semiconductor layer formed on a semiconductor substrate; a second semiconductor layer formed on the first semiconductor layer and having a conductivity type opposite to that of the first semiconductor layer; a pixel separation unit that divides a pixel region including the first semiconductor layer and the second semiconductor layer; a first electrode connected to the first semiconductor layer from one surface side of the semiconductor substrate; a metal layer connected to the second semiconductor layer from a light irradiation surface side which is the other surface of the semiconductor substrate, and buried in the pixel separation portion in at least a portion in a thickness direction of the semiconductor substrate; and a second electrode connected to the second semiconductor layer from the light irradiation surface side and formed to correspond to a position of the pixel separation portion; in, The metal layer is electrically connected to the second semiconductor layer via the second electrode.

2. The imaging device according to claim 1, wherein: The second electrode is formed along the periphery of the pixel area.

3. The imaging device according to claim 1, wherein: The second electrode is formed in a region that is a portion of a periphery of the pixel region.

4. The imaging device according to claim 3, wherein: The second electrode is formed in at least one of four corners of the rectangular pixel area.

5. The imaging device according to claim 3, wherein: The second electrode is buried in a hole formed in the second semiconductor layer.

6. The imaging device according to claim 3, wherein: The second electrode and the metal layer are formed of the same material.

7. The camera device according to claim 1, comprising: an insulating film formed along the pixel separation portion and the light irradiation surface, wherein The second electrode is embedded in an opening provided in the second semiconductor layer. A region is provided in which an end portion of the insulating film is retreated from a wall surface of the opening, and The region is filled with the second electrode.

8. The imaging device according to any one of claims 1 to 7, comprising: an insulating film formed along the pixel separation portion, wherein A region in which an end portion of the insulating film recedes in the thickness direction of the pixel separating portion is formed and is filled with the insulating film.

9. The imaging device according to any one of claims 1 to 7, wherein: A voltage for multiplying electrons is applied between the first electrode and the metal layer. 10 . The image pickup device according to claim 1 , comprising a third semiconductor layer formed on the second semiconductor layer and having the same conductivity type as that of the second semiconductor layer.

11. The imaging device according to claim 1, wherein: The second electrode is provided on an upper surface of the pixel separating portion.

12. The imaging device according to claim 1, wherein: The pixel separation portion and the second electrode have a planar shape of a grid shape surrounding the plurality of pixel regions.

Images